An electroluminescent device is a self-luminous display device and has been widely concerned due to the advantages of a wide viewing angle, high contrast, a high response speed, and etc. With the development in the electroluminescent field, the organic electroluminescent devices such as organic light emitting diode (OLED) display devices can achieve more excellent brightness, power consumption, response rate and color gamut compared with inorganic electroluminescent devices, and have become one of the mainstream in the current display market.